Backrest for park benches



FIG. 1 is a front-right-top perspective view of a backrest for park benches, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side view thereof, the opposite side being a mirror image; and,

FIG. 5 is a top plane view thereof, the opposite side being a mirror image. 

The ornamental design for a backrest for park benches, as shown and described. 